Background and purpose: Contrast-enhanced transcranial color-coded real-time sonography (TCCS) is a promising tool for the evaluation of brain circulation. The purpose of the present study was to assess the diagnostic ability of conventional and contrast-enhanced TCCS in patients with acute stroke and basilar artery occlusion and to compare the findings with those of angiography.
Methods: We prospectively performed conventional and contrast-enhanced TCCS within 3 days before or after digital subtraction angiography or MR angiography in 62 consecutive patients with acute ischemic stroke. We assigned the patients to two groups on the basis of angiographic findings: basilar artery occlusion group (n = 7) and control group without basilar artery occlusion (n = 55). We obtained basilar artery flow images showing the direction of blood flow using TCCS through a suboccipital window.
Results: In the control group, the detection rate of basilar artery flow using conventional and contrast-enhanced TCCS was 76.4% and 98.2%, respectively (P <.001), and the flow direction was antegrade in all patients. In the basilar artery occlusion group, neither conventional nor contrast-enhanced TCCS could obtain flow images of the proximal basilar artery in any patient. In five patients with proximal basilar artery occlusion, a reversed flow image in the distal basilar artery obtained by contrast-enhanced TCCS was confirmed by angiography to be blood supply through collateral circulation from the carotid systems. However, two patients with distal basilar artery occlusion did not have this sign.
Conclusion: Contrast-enhanced TCCS is more sensitive in imaging basilar artery flow than is conventional TCCS. When examined with contrast-enhanced TCCS, a combination of absent basilar artery flow and the reversed basilar artery flow sign may be a diagnostic indicator of basilar artery occlusion.